Methods including panel bonding acts and electronic devices including cavities

ABSTRACT

A method is disclosed. In one example, the method includes bonding a first panel of a first material to a base panel in a first gas atmosphere, wherein multiple hermetically sealed first cavities encapsulating gas of the first gas atmosphere are formed between the first panel and the base panel. The method further includes bonding a second panel of a second material to at least one of the base panel and the first panel, wherein multiple second cavities are formed between the second panel and the at least one of the base panel and the first panel.

CROSS-REFERENCE TO RELATED APPLICATION

This Utility Patent Application claims priority to German PatentApplication No. 10 2019 102 836.1, filed Feb. 5, 2019, which isincorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally relates to electronic devices andmethods for manufacturing thereof. In particular, the present disclosurerelates to methods including panel bonding acts and electronic devicesincluding cavities manufactured by such methods.

BACKGROUND

Electronic devices may include cavities housing electrical components ofthe devices. For example, moving parts of microelectromechanical systems(MEMS) may be arranged in cavities to ensure mechanical functionality ofthe moving parts. The cavities may be connected to the environment viaholes or channels for an exchange of fluids or gases. Manufacturers ofelectronic devices are constantly striving to improve their products andmethods for manufacturing thereof. It may thus be desirable to developmethods for manufacturing electronic devices that provide an improvedand cost-efficient production of the devices and that may beparticularly suited for the production of MEMS.

SUMMARY

An aspect of the present disclosure relates to a method. The methodcomprises bonding a first panel of a first material to a base panel in afirst gas atmosphere, wherein multiple hermetically sealed firstcavities encapsulating gas of the first gas atmosphere are formedbetween the first panel and the base panel. The method further comprisesbonding a second panel of a second material to at least one of the basepanel and the first panel, wherein multiple second cavities are formedbetween the second panel and the at least one of the base panel and thefirst panel.

A further aspect of the present disclosure relates to a method. Themethod comprises bonding a first panel of a first airtight material to abase panel in a first gas atmosphere, wherein multiple hermeticallysealed first cavities encapsulating gas of the first gas atmosphere areformed between the first panel and the base panel. The method furthercomprises bonding multiple caps of a second airtight material to atleast one of the base panel and the first panel in a second gasatmosphere different from the first gas atmosphere, wherein multiplehermetically sealed second cavities encapsulating gas of the second gasatmosphere are formed between the multiple caps and the at least one ofthe base panel and the first panel.

A further aspect of the present disclosure relates to a device. Thedevice comprises a first cavity formed by a first cap of an airtightmaterial bonded to a base, wherein the first cavity hermetically seals afirst gas and encapsulates a first electronic component. The devicefurther comprises a second cavity formed by a second cap of an airtightmaterial bonded to the base, wherein the second cavity hermeticallyseals a second gas different from the first gas and encapsulates asecond electronic component.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of aspects and are incorporated in and constitute a partof this description. The drawings illustrate aspects and together withthe description serve to explain principles of aspects. Other aspectsand many of the intended advantages of aspects will be readilyappreciated as they become better understood by reference to thefollowing detailed description. The elements of the drawings are notnecessarily to scale relative to each other. Like reference signs maydesignate corresponding similar parts.

FIG. 1 includes FIGS. 1A and 1B schematically illustrating across-sectional side view of a method for manufacturing a device inaccordance with the disclosure.

FIG. 2 includes FIGS. 2A and 2B schematically illustrating across-sectional side view of a method for manufacturing a device inaccordance with the disclosure.

FIG. 3 schematically illustrates a cross-sectional side view of a device300 in accordance with the disclosure.

FIG. 4 includes FIGS. 4A to 4E schematically illustrating across-sectional side view of a method for manufacturing a device 400 inaccordance with the disclosure.

FIG. 5 includes FIGS. 5A to 5E schematically illustrating across-sectional side view of a method for manufacturing a device 500 inaccordance with the disclosure.

FIG. 6 includes FIGS. 6A to 6D schematically illustrating across-sectional side view of a method for manufacturing a device 600 inaccordance with the disclosure.

FIG. 7 includes FIGS. 7A and 7B schematically illustrating a top viewand a cross-sectional side view of a panel 700, respectively, which maybe used in a method in accordance with the disclosure.

FIG. 8 schematically illustrates a cross-sectional side view of an actwhich may be applied in a method in accordance with the disclosure.

FIG. 9 schematically illustrates a cross-sectional side view of an actwhich may be applied in a method in accordance with the disclosure.

FIG. 10 schematically illustrates a cross-sectional side view of an actwhich may be applied in a method in accordance with the disclosure.

FIG. 11 schematically illustrates a cross-sectional side view of adevice 1100 in accordance with the disclosure.

FIG. 12 schematically illustrates a cross-sectional side view of adevice 1200 in accordance with the disclosure.

FIG. 13 schematically illustrates a cross-sectional side view of adevice 1300 in accordance with the disclosure.

FIG. 14 illustrates a flowchart of a method in accordance with thedisclosure.

FIG. 15 illustrates a flowchart of a method in accordance with thedisclosure.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, in which are shown by way of illustrationspecific aspects in which the disclosure may be practiced. In thisregard, directional terminology, such as “top”, “bottom”, “front”,“back”, etc. may be used with reference to the orientation of thefigures being described. Since components of described devices may bepositioned in a number of different orientations, the directionalterminology may be used for purposes of illustration and is in no waylimiting. Other aspects may be utilized and structural or logicalchanges may be made without departing from the concept of the presentdisclosure. Hence, the following detailed description is not to be takenin a limiting sense, and the concept of the present disclosure isdefined by the appended claims.

FIG. 1 includes FIGS. 1A and 1B schematically illustrating across-sectional side view of a method for manufacturing a device inaccordance with the disclosure. The method of FIG. 1 is illustrated in ageneral manner in order to qualitatively specify aspects of thedisclosure. The method may include further aspects which are notillustrated for the sake of simplicity. For example, the method may beextended by any of the aspects described in connection with othermethods and devices in accordance with the disclosure.

In FIG. 1A, a first panel 2 of a first material is bonded to a basepanel 4 in a first gas atmosphere. For the bonding act, the first panel2 and the base panel 4 may be placed in a bonding chamber (notillustrated) configured to provide the first gas atmosphere. It is notedthat herein the term “panel” may be used synonymously with the term“wafer”. After the bonding act, multiple hermetically sealed firstcavities 6A encapsulating gas 8 of the first gas atmosphere are formedbetween the first panel 2 and the base panel 4. In FIG. 1A, theencapsulated gas 8 is illustrated by dots. In the example of FIG. 1A,only two first cavities 6A are illustrated for the sake of simplicity.In further examples, the number of formed first cavities 6A may differin an arbitrary manner. For example, the first panel 2 may be used formanufacturing several hundreds or thousands of MEMS devices, whereineach of the manufactured devices may include only one of the firstcavities 6A. For example, at least one of the first cavities 6A maybecome a part of a photoacoustic gas sensor that is to be manufactured.In such case, an IR emitter and a protective gas may be enclosed in thefirst cavity 6A.

In FIG. 1B, a second panel 20 of a second material is bonded to at leastone of the base panel 4 and the first panel 2. Multiple second cavities6B are formed between the second panel 20 and the at least one of thebase panel 4 and the first panel 2. In the example of FIG. 1B, thesecond panel 20 may be bonded to the base panel 4. A further example inwhich the second panel is bonded to the first panel instead of the basepanel is shown and described in connection with FIG. 6.

According to an embodiment the second panel 20 may be bonded in a secondgas atmosphere different from the first gas atmosphere. In addition, thesecond cavities 6B may be hermetically sealed and may encapsulate gas ofthe second gas atmosphere. For example, at least one of the secondcavities 6B may become a part of a photoacoustic gas sensor that is tobe manufactured. In such case, a microphone and a reference gas may beenclosed in the second cavity 6B. In an alternative embodiment, thesecond cavities 6B may not necessarily be hermetically sealed, but maybe connected to the environment via one or more holes and/or channelsarranged in the second panel 20.

According to an embodiment the bonded panels 2, 4 and 20 may besingulated into multiple devices to be manufactured. The singulationprocess may include an etching process, a plasma dicing process, anultrasonic mechanical dicing process, a laser dicing process, or acombination thereof. Each of the devices may include at least twocavities, wherein a first cavity of the at least two cavities mayinclude gas of the first gas atmosphere and a second cavity of the atleast two cavities may include gas of the second gas atmosphere. Forexample, a manufactured device may be a photoacoustic gas sensor,wherein the first cavity may enclose an IR emitter and a protective gasand the second cavity may enclose a microphone and a reference gas.

According to an embodiment at least one of the first material and thesecond material may be airtight. That is, the respective material may beconfigured to exclude a passage of air, oxygen, or other gases. Theairtight material may be configured to form hermetically sealed cavitiesin which electronic components may be safely arranged. The electroniccomponents may thus be secured against external influences, such as e.g.humidity, so that a proper functioning and reliability of the electroniccomponents may be ensured. In addition, certain electronic components,such as e.g. a microphone, may require cavities encapsulating a definedgas having a constant concentration.

According to an embodiment at least one of the first material and thesecond material may include at least one of a semiconductor material, aglass material, a ceramic material. In particular, these materials maybe airtight. In one example, a glass material may form a panel which maybe made of or may include at least one of quartz, fused silica,borosilicate glass, etc. In a further example, a ceramic material mayform a panel which may be made of or may include at least one of an LTCC(Low Temperature Cofired Ceramics) multilayer ceramic material, a HTCC(High Temperature Cofired Ceramics) multilayer ceramic material, etc. Inyet a further example, a semiconductor material may form a panel whichmay be made of or may include at least one an elemental semiconductormaterial, such as e.g. Si, and a compound semiconductor material, suchas e.g. GaN, SiC, SiGe, GaAs. The panels 2, 4 and 20 may be made of asame material or of different materials depending on the type of thedevices that are to be manufactured.

According to an embodiment at least one of the first panel 2 and thesecond panel 20 may include multiple recesses, may be bonded to a planarsurface of the base panel 4, and the cavities formed between the basepanel 4 and the at least one of the first panel 2 and the second panel20 may be formed by sections of the planar surface and the recesses. Inthe example of FIG. 1, the first cavities 6A may be formed betweenrecesses arranged in the lower surface of the first panel 2 and theupper planar surface of the base panel 4. In a further example, thefirst cavities 6A may be formed between recesses in the upper surface ofthe base panel 4 and a planar lower surface of the first panel 2 facingthe base panel 4. In yet a further example, the first cavities 6A may beformed between recesses in the upper surface of the base panel 4 andrecesses in the lower surface of the first panel 2. In such case, therecesses in the first panel 2 and the base panel 4 may be at leastpartly aligned to each other such that cavities may be formed by arecess in the first panel 2 and a recess in the base panel 4,respectively. Alternatively, the recesses in the first panel 2 and thebase panel 4 may be displaced with respect to each other such thatcavities may be formed only by a recess in the first panel 2 or only bya recess in the base panel 4. It is noted that above comments also holdtrue for the second cavities 6B formed between the base panel 4 and thesecond panel 20.

According to an embodiment the first panel 2 and the second panel 20 maybe bonded to opposite surfaces of the base panel 4 as exemplarily shownin FIG. 1. Here, the first cavities 6A and the second cavities 6Barranged on opposite surfaces of the base panel 4 may be displaced oraligned to each other. Examples of electronic devices in accordance withthe disclosure including cavities arranged on opposite sides of a baseare shown and described in connection with FIGS. 3, 11 and 13.

According to an embodiment the first panel 2 and the second panel 20 maybe bonded to a same surface of the base panel 4. Examples of methods inaccordance with the disclosure including such act are shown anddescribed in connection with FIGS. 4 and 5. An example of a device inaccordance with the disclosure including cavities on a same side of abase is shown and described in connection with FIG. 12.

According to an embodiment the second panel 20 may be bonded to thefirst panel 2, and the second cavities 6B may be stacked over the firstcavities 6A. An example of a method in accordance with the disclosureincluding such act is shown and described in connection with FIG. 6.Such method may e.g. be used for manufacturing MEMS devices having avertical structure.

According to an embodiment at least one of bonding the first panel 2 andbonding the second panel 20 may include at least one of anodic bonding,soldering, gluing, metal-to-metal bonding. Anodic bonding may refer to apanel bonding technique for sealing glass to either silicon or metalwithout introducing an intermediate layer. Anodic bonding may becommonly used to seal glass to silicon wafers in electronics andmicrofluidics. In addition, other materials may be used for anodicbonding with silicon, for example LTCC. Soldering may e.g. refer toeutectic soldering (or eutectic bonding) which may relate to a panelbonding technique with an intermediate metal layer that can produce aeutectic system. For example, eutectic bonding may be used for Si-Sibonding or Si-glass bonding. Gluing may e.g. refer to adhesive bonding(or glue bonding) which may relate to a panel bonding techniqueincluding applying an intermediate layer to connect panels of differenttypes of materials. An applied adhesive may be organic or inorganic, forexample SU-8, benzocyclobutene (BCB), etc. Metal-to-metal bonding mayrefer to a panel bonding technique in which metal films may be used asbonding layers at panel-level. In particular, copper-to-copper bondingtechniques may be used.

According to an embodiment material from the first panel 2 may be atleast partially removed before bonding the second panel 20. For example,the first panel 2 and the second panel 20 may both be bonded to a samesurface of the base panel 4. Before bonding the second panel 20, thebonded first panel 2 may substantially occupy the entire surface of thebase panel 4. In order to provide surface area for bonding the secondpanel 20, parts of the first panel 2 may be removed. An exemplary act ofremoving material from a first panel before bonding a second panel isshown and described in connection with FIG. 4B. Removing material fromthe first panel 2 may e.g. include at least one of etching, dicing,chemical mechanical polishing, grinding, punching, stamping, etc.

According to an embodiment electronic components may be arranged overthe base panel 4 before bonding the first panel 2 and bonding the secondpanel 20. At least one of the electronic components may be arranged inat least one of the first cavities 6A and the second cavities 6B afterbonding the first panel 2 and bonding the second panel 20. Alternativelyor additionally, the electronic components in the cavities 6A and 6B mayhave been arranged over at least one of the first panel 2 and the secondpanel 20 before the bonding act(s). In general, the electroniccomponents may be any kind of electronic components that may be used ina MEMS device, a microfluidic device, a lab-on-a-chip device, etc. Suchdevices may inter alia include micromechanical elements, sensors,actuators, etc. A sensor (or sensor chip) may embed micromechanicalstructures and may further include electronic circuits configured toprocess electrical signals generated by the micromechanical structures.Alternatively or additionally, a logic (semiconductor) chip may becoupled to the sensor chip, wherein the logic chip may be configured toprocess electrical signals provided by the sensor chip. For example, thelogic chip may include an application specific integrated circuit(ASIC). In one specific example, a photoacoustic gas sensor may includean IR emitter, a microphone, and an ASIC.

According to an embodiment the base panel 4 may be made of or mayinclude a semiconductor material. The semiconductor material may be atleast one of an elemental semiconductor material, such as e.g. Si, and acompound semiconductor material, such as e.g. GaN, SiC, SiGe, GaAs. Themethod of FIG. 1 may further include an act of integrating electroniccomponents in the semiconductor material of the base panel 4 beforebonding the first panel 2 and bonding the second panel 20. Again, theelectronic components may be any kind of electronic components that maybe used in a MEMS device, a microfluidic device, a lab-on-a-chip device,etc. At least one of the integrated electronic components may bearranged in at least one of the first cavities 6A and the secondcavities 6B after bonding the first panel 2 and bonding the second panel20. Alternatively or additionally, at least one of the first panel 2 andthe second panel 20 may be made of or may include a semiconductormaterial, wherein the integrated electronic components arranged in thecavities may also be at least partly integrated in the semiconductormaterial of the first panel 2 and/or the second panel 20.

According to an embodiment at least one of the base panel 4, the firstpanel 2 and the second panel 20 may include one or more from a groupconsisting of: electrical through connections, conductor lines,electrical redistribution layers, optical connections, fluidicconnections. An electrical through connection may e.g. be formed as avia connection, for example a Through Silicon Via (TSV). The electricalthrough connection may be part of a redistribution layer. Aredistribution layer may include one or more layers of a ceramic ordielectric material. Structures for routing and redistributingelectrical signals may be embedded in these layers. The signal routingstructures may include vias and conductor lines. The conductor lines maybe arranged in different planes between the ceramic or dielectric layersand may be electrically connected to each another via electrical throughconnections extending substantially vertically to the layers. Forexample, a redistribution layer may provide an electrical connectionbetween electrical contacts arranged on opposite surfaces of a panel.

An optical connection may provide a path that allows a transmission ofelectromagnetic radiation through a material. It is noted that hereinthe term “optical” may generally refer to electromagnetic radiation ofany wavelength. In particular, the electromagnetic radiation may be inthe infrared (IR) range, but electromagnetic radiation of otherwavelengths may be possible as well. For example, an optical connectionmay be provided by using a material which is transparent to thetransmitted electromagnetic radiation. In one example, an opticalconnection for IR radiation may be provided by using an IR transparentsilicon material. A fluidic connection may provide a path that allows atransmission of a fluid through a material. The fluid may e.g. be a gasor a liquid. For example, a fluidic connection may be provided bychannels or holes extending through the material.

FIG. 2 includes FIGS. 2A and 2B schematically illustrating across-sectional side view of a method for manufacturing a device inaccordance with the disclosure. The method of FIG. 2 is illustrated in ageneral manner in order to qualitatively specify aspects of thedisclosure. The method may include further aspects which are notillustrated for the sake of simplicity. For example, the method may beextended by any of the aspects described in connection with othermethods and devices in accordance with the disclosure. The method ofFIG. 2 may be at least partly similar to the method of FIG. 1 such thatcomments in connection with FIG. 1 may also hold true for FIG. 2.

In FIG. 2A, a first panel 2 of a first airtight material is bonded to abase panel 4 in a first gas atmosphere. Multiple hermetically sealedfirst cavities 6A encapsulating gas 8 of the first gas atmosphere areformed between the first panel 2 and the base panel 4. The act of FIG.2A may be similar to the act of FIG. 1A.

In FIG. 2B, multiple caps 10 of a second airtight material are bonded toat least one of the base panel 4 and the first panel 2 in a second gasatmosphere different from the first gas atmosphere. Multiplehermetically sealed second cavities 6B encapsulating gas 12 of thesecond gas atmosphere are formed between the multiple caps 10 and the atleast one of the base panel 4 and the first panel 2. In FIG. 2B, theencapsulated gas 12 is illustrated by small circles. In the example ofFIG. 2B, each of the second cavities 6B may be formed by one of the caps10. In further examples, a cap 10 may be shaped in a way such thatmultiple second cavities 6B may be formed between the specific cap 10and the base panel 4.

According to an embodiment an arrangement including the base panel 4,the first panel 2 and the multiple caps 10 may be singulated intomultiple devices. Each of the devices may include at least two cavities,wherein a first cavity of the at least two cavities may include gas 8 ofthe first gas atmosphere and a second cavity of the at least twocavities may include gas 12 of the second gas atmosphere. In the exampleof FIG. 2B, the arrangement may e.g. be singulated along a vertical lineextending between the first cavities 6A and the second cavities 6B,respectively.

FIG. 3 schematically illustrates a cross-sectional side view of a device300 in accordance with the disclosure. The device 300 is illustrated ina general manner in order to qualitatively specify aspects of thedisclosure. The device 300 may include further components which are notillustrated for the sake of simplicity. For example, the device 300 maybe extended by any of the aspects described in connection with otherdevices and methods in accordance with the disclosure. In one example,the device 300 may be manufactured according to one of the methods ofFIGS. 1 and 2.

The device 300 includes a first cavity 6A formed by a first cap 10A ofan airtight material bonded to a base 14. The first cavity 6Ahermetically seals a first gas 8 and encapsulates a first electroniccomponent 16A. The device 300 further includes a second cavity 6B formedby a second cap 10B of an airtight material bonded to the base 14. Thesecond cavity 6B hermetically seals a second gas 12 different from thefirst gas 8 and encapsulates a second electronic component 16B.

According to an embodiment the base 14 may include a semiconductormaterial and at least one of the first electronic component 16A and thesecond electronic component 16B may be integrated in the semiconductormaterial.

According to an embodiment the device 300 may include at least one of aMEMS, a microfluidic system, a lab-on-a-chip.

According to an embodiment the device 300 may include a photoacousticgas sensor, wherein the first electronic component 16A may be or mayinclude an IR emitter and the first gas 8 may be a protective gas. Forexample, the protective gas may be nitrogen or a noble gas, such as e.g.argon, xenon, krypton. In addition, the second electronic component 16Bmay be or may include a microphone, and the second gas 12 may be areference gas. For example, the reference gas may be carbon dioxide,nitrogen oxide, methane, ammonia. The second electronic component 16Bmay further include an ASIC configured to process electrical signalsprovided by the microphone.

FIG. 4 includes FIGS. 4A to 4E schematically illustrating across-sectional side view of a method for manufacturing a device 400 inaccordance with the disclosure. For example, the method of FIG. 4 may beseen as a more detailed implementation of the methods of FIGS. 1 and 2.

In FIG. 4A, a first panel 2 may be bonded to a base panel 4 in a firstgas atmosphere. For this purpose, the first panel 2 and the base panel 4may be placed in a bonding chamber (not illustrated) configured toprovide the first gas atmosphere. The bonding act may include at leastone of anodic bonding, soldering, gluing, metal-to-metal bonding,depending on the materials of the first panel 2 and the base panel 4.Each of the first panel 2 and the base panel 4 may be made of anairtight material, such as e.g. at least one of a semiconductormaterial, a glass material, a ceramic material. The first panel 2 mayinclude multiple recesses 18 formed in the lower surface of the firstpanel 2. The upper surface of the base panel 4 may be substantiallyplanar. For example, the gas 8 of the first gas atmosphere may be aprotective gas, e.g. nitrogen or a noble gas, such as argon, xenon,krypton.

In FIG. 4B, multiple hermetically sealed first cavities 6A encapsulatingthe gas 8 of the first gas atmosphere may be formed between the firstpanel 2 and the base panel 4 after the bonding act. In a further act(see arrows), material of the first panel 2 arranged between the firstcavities 6A may be removed. For example, the material may be removed byapplying at least one of etching, dicing, punching, stamping, etc.

In FIG. 4C, the arrangement may be placed in a bonding chamber (notillustrated) providing a second gas atmosphere. The bonding chamber maybe the same bonding chamber as used in the act of FIG. 4A or may differtherefrom. For example, the gas 12 of the second gas atmosphere may be areference gas, such as e.g. carbon dioxide, nitrogen oxide, methane,ammonia.

In FIG. 4D, multiple caps 10 may be bonded to the base panel 4. The caps10 may be arranged between the first cavities 6A as exemplarily shown inFIG. 4D, but may also be placed elsewhere depending on the type ofdevice to be manufactured. The caps 10 may be made of an airtightmaterial, such as e.g. at least one of a semiconductor material, a glassmaterial, a ceramic material. The bonding act may include at least oneof anodic bonding, soldering, gluing, metal-to-metal bonding, dependingon the materials of the base panel 4 and the caps 10. Multiplehermetically sealed cavities 6B encapsulating gas 12 of the second gasatmosphere may be formed between the base panel 4 and the caps 10 afterthe bonding act.

In FIG. 4E, the arrangement may be singulated into multiple devices 400(see arrow). The singulation process may include an etching process, aplasma dicing process, an ultrasonic mechanical dicing process, a laserdicing process, or a combination thereof. Each of the devices 400 mayinclude two cavities 6A and 6B. The first cavity 6A may include gas 8 ofthe first gas atmosphere, and the second cavity 6B may include gas 12 ofthe second gas atmosphere.

The method of FIG. 4 may include further acts which are not illustratedfor the sake of simplicity. In one example, the method may include anyfurther act required for manufacturing a device similar to the device1200 of FIG. 12. In particular, a further exemplary act may includearranging electronic components in the cavities 6A and 6B.

In the example of FIG. 4, the first cavities 6A and the second cavities6B may be hermetically sealed and filled with a defined gas,respectively. In further examples, at least one of the first cavities 6Aand the second cavities 6B may include one or more holes, openings orchannels providing one or more connections between the respectivecavities and the environment. Examples of such devices are shown anddescribed in connection with FIGS. 11 and 13.

FIG. 5 includes FIGS. 5A to 5E schematically illustrating across-sectional side view of a method for manufacturing a device 500 inaccordance with the disclosure. The method of FIG. 5 may at least partlybe similar to the method of FIG. 4 such that comments made in connectionwith FIG. 4 may also hold true for FIG. 5.

In FIG. 5A, an arrangement including multiple hermetically sealed firstcavities 6A between a first panel 2 and a base panel 4 may be provided.A first gas 8 may be encapsulated in the first cavities 6A. For example,the arrangement may be manufactured by acts similar to the acts of FIGS.4A to 4B.

In FIG. 5B, a second panel 20 may be bonded to the base panel 4 in asecond gas atmosphere.

In FIG. 5C, multiple hermetically sealed second cavities 6Bencapsulating gas 12 of the second gas atmosphere may be formed betweenthe second panel 20 and the base panel 4 after the bonding act. In afurther act (see arrows) similar to the act of FIG. 4B, material of thesecond panel 20 arranged between the second cavities 6B may be removed.

FIG. 5D shows the arrangement after removing the material of the secondpanel 20. The arrangement may include multiple first cavities 6Ahermetically encapsulating the first gas 8 as well as multiple secondcavities 6B hermetically encapsulating the second gas 12.

In FIG. 5E, the arrangement may be singulated into multiple devices 500(see arrow). The singulation process of FIG. 5E may be similar to thesingulation process of FIG. 4E.

FIG. 6 includes FIGS. 6A to 6D schematically illustrating across-sectional side view of a method for manufacturing a device 600 inaccordance with the disclosure. The method of FIG. 6 may be at leastpartly similar to the methods of FIGS. 4 and 5.

In FIG. 6A, a first panel 2 may be bonded to a base panel 4 in a firstgas atmosphere.

In FIG. 6B, multiple hermetically sealed first cavities 6A encapsulatinggas 8 of the first gas atmosphere may be formed between the first panel2 and the base panel 4 after the bonding act. In a further act, a secondpanel 20 may be bonded to the first panel 2 in a second gas atmosphere.

In FIG. 6C, multiple hermetically sealed second cavities 6Bencapsulating gas 12 of the second gas atmosphere may be formed betweenthe second panel 20 and the first panel 2 after the bonding act. As aresult, the second cavities 6B may be stacked over the first cavities6A. In particular, such arrangement of stacked cavities may be chosenwhen devices with a vertical structure are to be manufactured.

In FIG. 6D, the arrangement may be singulated into multiple devices 600(see arrow). The singulation process of FIG. 6D may be similar to thesingulation process of FIG. 4E.

FIG. 7 includes FIGS. 7A and 7B schematically illustrating a panel 700which may be used in a method in accordance with the disclosure. FIG. 7Ashows a top view of the panel 700. FIG. 7B shows a cross-sectional sideview of the panel 700 along a dashed line in the top view of FIG. 7A.

The panel 700 may include multiple recesses 18 and multiple openings 22.In the top view of FIG. 7A the recesses 18 are indicated by hatchedareas, but may in reality be covered in such perspective. Forillustrative purposes, FIG. 7 only shows a part or section of the panel700. It is noted that the panel 700 may include an arbitrary number offurther recesses 18 and further openings 20 which may be arranged ine.g. a rectangular and periodic grid structure when viewed in the topview. For example, the panel 700 may be used for manufacturing severalhundreds or thousands of MEMS devices such that an corresponding numberof recesses 18 and openings 20 may need to be provided. The panel 700may be formed as a single-piece (or integral) part or may includemultiple parts that may be joined together.

FIGS. 8 to 10 schematically illustrate cross-sectional side views ofacts which may be applied in a method in accordance with the disclosure.For example, any of the acts of FIGS. 8 to 10 may be used in one of thepreviously specified methods.

In FIG. 8, a panel 2 may be bonded to a base panel 4 in order to formcavities that may particularly be hermetically sealed. In the example ofFIG. 8, one or more of the cavities may be formed between recesses 18 ina lower surface of the panel 2 and a planar upper surface of the basepanel 4. The panel 2 may be made of or may include a semiconductormaterial, for example an elemental semiconductor material, such as e.g.Si, or a compound semiconductor material, such as e.g. GaN, SiC, SiGe,GaAs. Multiple electronic components 16 may be integrated in thesemiconductor material of the panel 2. In general, the location of theintegrated electronic components 16 in the panel 2 may depend on thetype of device that is to be manufactured. In the example of FIG. 8, theelectronic components 16 may be located between the recesses 18 in theupper surface of the panel 2. Depending on the type of device that is tobe manufactured, the electronic components 16 may be similar or differfrom each other. In general, the electronic components 16 may be anykind of electronic component that may be used in a MEMS device, amicrofluidic device, a lab-on-a-chip device, etc.

In contrast to FIG. 8, the electronic components 16 in FIG. 9 may bearranged between the recesses 18 in the lower surface of the panel 2. Inaddition, one or more of the electronic components 16 may includerecesses 24 which may be arranged in a lower surface of the respectiveelectronic component 16. When bonding the panel 2 to the base panel 4,additional cavities may be formed between the recesses 24 of theelectronic components 16 and the upper surface of the base panel 4. Forexample, an electronic component 16 with a recess 24 may include a MEMSstructure.

The act of FIG. 10 may at least partly be similar to the act of FIG. 9.In addition, the panel 2 may include further recesses 26 which may bearranged in the upper surface of the panel 2. For example, the recesses26 may form additional cavities when a further panel (not illustrated)may be bonded to the upper surface of the panel 2.

FIG. 11 schematically illustrates a cross-sectional side view of adevice 1100 in accordance with the disclosure. For example, the device1100 may be seen as a more detailed implementation of the device 300 ofFIG. 3. The device 1100 may be manufactured by any of the previouslydescribed methods.

The device 1100 may include a base 14 with substantially planar upperand lower surfaces. A first cap 10A may be arranged over the uppersurface of the base 14, thereby forming a hermetically sealed firstcavity 6A. For example, the first cap 10A may be obtained by singulatinga panel in an act during the fabrication of the device 1100. The firstcap 10A may include one or more reflective structures 32A, 32B which maybe arranged on the inner walls of the first cap 10A. In particular, thereflective structures 32A, 32B may be configured to reflect IRradiation. An IR emitter 28 may be mounted on the upper surface of thebase 14 inside the first cavity 6A. The IR emitter 28 may beelectrically coupled to electrical signal routing structures of the base14. In addition, the first cavity 6A may be filled with a protective gas30, for example nitrogen or a noble gas, such as e.g. argon, xenon,krypton.

A second cap 10B may be arranged over the lower surface of the base 14,thereby forming a second cavity 6B and a third cavity 6C. For example,the second cap 10B may be obtained by singulating a panel in an actduring the fabrication of the device 1100. The second cavity 6B may behermetically sealed while the third cavity 6C may be connected to theenvironment via one or more holes 34 arranged in the second cap 10B. Amicrophone 36 and an ASIC 38 may be mounted on the lower surface of thebase 14 inside the second cavity 6B. The ASIC 38 may be configured toprocess electrical signals provided by the microphone 36. The microphone36 and the ASIC 38 may be electrically coupled to electrical signalrouting structures of the base 14. In addition, the second cavity 6B maybe filled with a reference gas 40, such as e.g. carbon dioxide, nitrogenoxide, methane, ammonia. The second cap 10B may include one or morereflective structures 32C similar to the first cap 10A.

The device 1100 may be operated as a photoacoustic gas sensor fordetecting and quantifying a certain gas or a certain gas component inthe environment. In particular, the photoacoustic gas sensor may beconfigured to operate based on electromagnetic radiation in the IRrange. However, similar photoacoustic gas sensors operating on the basisof electromagnetic radiation of other wavelengths may be possible aswell. The reference gas 40 may serve as a reference for the certain gasthat is to be detected. That is, the reference gas 40 may provide arelatively high concentration of the certain gas type. The IR emitter 28may be configured to provide an IR pulse which may be a broadband pulseincluding wavelengths corresponding to excitation energies of thecertain gas. The emitted IR pulse may propagate along a path (see dashedline), wherein the IR pulse may be reflected at the reflectivestructures 32A and 32B arranged on the inner walls of the first cap 10Aand may further pass through the material (e.g. silicon) of the base 14.When propagating through the third cavity 6C, the IR pulse may at leastpartly be absorbed by portions of the certain gas, if present in thethird cavity 6C (i.e. in the environment). The absorption may bespecific for the certain gas, e.g. characteristic rotational orvibrational modes of atoms or molecules of the certain gas. The IR pulsemay further propagate through the material (e.g. silicon) of the secondcap 10B to the second cavity 6B and may be at least partly absorbed bythe reference gas 40 and may provoke a local pressure increase in thereference gas 40 which may be sensed by the microphone 36. The signalsensed by the microphone 36 may be used for a detection andquantification of the certain gas in the environment.

FIG. 12 schematically illustrates a cross-sectional side view of adevice 1200 in accordance with the disclosure. The device 1200 may atleast partly be similar to the device 1100 of FIG. 11. In contrast toFIG. 11, the first cap 10A and the second cap 10B may both be arrangedon a same surface of the base 14. In a further contrast to FIG. 11, thefirst cap 10A may include only one reflective structure 32A arranged onthe inner walls of the first cap 10A. In yet a further contrast to FIG.11, the second cap 10B may include only the second cavity 6Bencapsulating the reference gas 40, but may not necessarily include thethird cavity 3C connected to the environment. In the example of FIG. 12,the IR pulse propagates through the environment (which may includepossible portions of the certain gas that is to be detected) whenpassing a section located between the first cap 10A and the second cap10B (see section of dashed line between caps 10A and 10B).

FIG. 13 schematically illustrates a cross-sectional side view of adevice 1300 in accordance with the disclosure. The device 1300 may atleast partly be similar to the device 1100 of FIG. 11. In contrast toFIG. 11, the second cap 10B may not necessarily form the second cavity6B encapsulating the reference gas 40, but may only form the thirdcavity 6C connected to the environment via a hole 34. In the example ofFIG. 13, the IR emitter 28 may be configured to emit an IR pulse whichmay only include wavelengths of interest corresponding to excitationenergies of the certain gas that is to be detected. An additional filter(not illustrated) configured to filter the output of the IR emitter 28may be used for providing a corresponding filtered IR pulse.

FIG. 14 illustrates a flowchart of a method in accordance with thedisclosure. The method may be similar to and may be read in connectionwith the method of FIG. 1.

At 42, a first panel of a first material is bonded to a base panel in afirst gas atmosphere. Multiple hermetically sealed first cavitiesencapsulating gas of the first gas atmosphere are formed between thefirst panel and the base panel. At 44, a second panel of a secondmaterial is bonded to at least one of the base panel and the firstpanel. Multiple second cavities are formed between the second panel andthe at least one of the base panel and the first panel.

FIG. 15 illustrates a flowchart of a method in accordance with thedisclosure. The method may be similar to and may be read in connectionwith the method of FIG. 2.

At 46, a first panel of a first airtight material is bonded to a basepanel in a first gas atmosphere. Multiple hermetically sealed firstcavities encapsulating gas of the first gas atmosphere are formedbetween the first panel and the base panel. At 48, multiple caps of asecond airtight material are bonded to at least one of the base paneland the first panel in a second gas atmosphere different from the firstgas atmosphere. Multiple hermetically sealed second cavitiesencapsulating gas of the second gas atmosphere are formed between themultiple caps and the at least one of the base panel and the firstpanel.

EXAMPLES

In the following, methods including panel bonding acts and electronicdevices including cavities will be explained by means of examples.

Example 1 is a method, comprising: bonding a first panel of a firstmaterial to a base panel in a first gas atmosphere, wherein multiplehermetically sealed first cavities encapsulating gas of the first gasatmosphere are formed between the first panel and the base panel; andbonding a second panel of a second material to at least one of the basepanel and the first panel, wherein multiple second cavities are formedbetween the second panel and the at least one of the base panel and thefirst panel.

Example 2 is a method according to Example 1, wherein the second panelis bonded in a second gas atmosphere different from the first gasatmosphere, and the second cavities are hermetically sealed andencapsulate gas of the second gas atmosphere.

Example 3 is a method according to Example 2, further comprising:singulating the bonded panels into multiple devices, wherein each of thedevices comprises at least two cavities, wherein a first cavity of theat least two cavities comprises gas of the first gas atmosphere and asecond cavity of the at least two cavities comprises gas of the secondgas atmosphere.

Example 4 is a method according to one of the preceding claims Examples,wherein at least one of the first material and the second material isairtight.

Example 5 is a method according to one of the preceding Examples,wherein at least one of the first material and the second materialcomprises at least one of a semiconductor material, a glass material, aceramic material.

Example 6 is a method according to one of the preceding Examples,wherein at least one of the first panel and the second panel: comprisesmultiple recesses, is bonded to a planar surface of the base panel, andthe cavities formed between the base panel and the at least one of thefirst panel and the second panel are formed by sections of the planarsurface and the recesses.

Example 7 is a method according to one of the preceding Examples,wherein the first panel and the second panel are bonded to a samesurface of the base panel.

Example 8 is a method according to one of Examples 1 to 6, wherein thefirst panel and the second panel are bonded to opposite surfaces of thebase panel.

Example 9 is a method according to one of Examples 1 to 6, wherein thesecond panel is bonded to the first panel, and the second cavities arestacked over the first cavities.

Example 10 is a method according to one of the preceding Examples,wherein at least one of bonding the first panel and bonding the secondpanel comprises at least one of anodic bonding, soldering, gluing,metal-to-metal bonding.

Example 11 is a method according to one of the preceding Examples,further comprising: at least partially removing material from the firstpanel before bonding the second panel.

Example 12 is a method according to one of the preceding Examples,further comprising: arranging electronic components over the base panelbefore bonding the first panel and bonding the second panel, wherein atleast one of the electronic components is arranged in at least one ofthe first cavities and the second cavities after bonding the first paneland bonding the second panel.

Example 13 is a method according to one of the preceding Examples,wherein the base panel comprises a semiconductor material and the methodfurther comprises: integrating electronic components in thesemiconductor material of the base panel before bonding the first paneland bonding the second panel, wherein at least one of the integratedelectronic components is arranged in at least one of the first cavitiesand the second cavities after bonding the first panel and bonding thesecond panel.

Example 14 is a method according to one of the preceding Examples,wherein at least one of the base panel, the first panel and the secondpanel comprises one or more from a group consisting of: electricalthrough connections, conductor lines, electrical redistribution layers,optical connections, fluidic connections.

Example 15 is a method, comprising: bonding a first panel of a firstairtight material to a base panel in a first gas atmosphere, whereinmultiple hermetically sealed first cavities encapsulating gas of thefirst gas atmosphere are formed between the first panel and the basepanel; and bonding multiple caps of a second airtight material to atleast one of the base panel and the first panel in a second gasatmosphere different from the first gas atmosphere, wherein multiplehermetically sealed second cavities encapsulating gas of the second gasatmosphere are formed between the multiple caps and the at least one ofthe base panel and the first panel.

Example 16 is a method according to Example 15, further comprising:singulating an arrangement comprising the base panel, the first paneland the multiple caps into multiple devices, wherein each of the devicescomprises at least two cavities, wherein a first cavity of the at leasttwo cavities comprises gas of the first gas atmosphere and a secondcavity of the at least two cavities comprises gas of the second gasatmosphere.

Example 17 is a device, comprising: a first cavity formed by a first capof an airtight material bonded to a base, wherein the first cavityhermetically seals a first gas and encapsulates a first electroniccomponent; and a second cavity formed by a second cap of an airtightmaterial bonded to the base, wherein the second cavity hermeticallyseals a second gas different from the first gas and encapsulates asecond electronic component.

Example 18 is a device according to Example 17, wherein the basecomprises a semiconductor material and at least one of the firstelectronic component and the second electronic component is integratedin the semiconductor material.

Example 19 is a device according to Example 17 or 18, wherein the devicecomprises at least one of a microelectromechanical system, amicrofluidic system, a lab-on-a-chip.

Example 20 is a device according to one of Examples 17 to 19, whereinthe device comprises a photoacoustic gas sensor, the first electroniccomponent comprises an IR emitter, the second electronic componentcomprises a microphone, the first gas is a protective gas, and thesecond gas is a reference gas.

As employed in this description, the terms “connected”, “coupled”,“electrically connected” and/or “electrically coupled” may notnecessarily mean that elements must be directly connected or coupledtogether. Intervening elements may be provided between the “connected”,“coupled”, “electrically connected” or “electrically coupled” elements.

Further, the word “over” used with regard to e.g. a material layerformed or located “over” a surface of an object may be used herein tomean that the material layer may be located (e.g. formed, deposited,etc.) “directly on”, e.g. in direct contact with, the implied surface.The word “over” used with regard to e.g. a material layer formed orlocated “over” a surface may also be used herein to mean that thematerial layer may be located (e.g. formed, deposited, etc.) “indirectlyon” the implied surface with e.g. one or more additional layers beingarranged between the implied surface and the material layer.

Furthermore, to the extent that the terms “having”, “containing”,“including”, “with” or variants thereof are used in either the detaileddescription or the claims, such terms are intended to be inclusive in amanner similar to the term “comprising”. That is, as used herein, theterms “having”, “containing”, “including”, “with”, “comprising” and thelike are open-ended terms that indicate the presence of stated elementsor features, but do not preclude additional elements or features.

Moreover, the word “exemplary” is used herein to mean serving as anexample, instance, or illustration. Any aspect or design describedherein as “exemplary” is not necessarily to be construed as advantageousover other aspects or designs. Rather, use of the word “exemplary” isintended to present concepts in a concrete fashion.

Devices and methods for manufacturing devices are described herein.Comments made in connection with a described device may also hold truefor a corresponding method and vice versa. For example, if a specificcomponent of a device is described, a corresponding method formanufacturing the device may include an act of providing the componentin a suitable manner, even if such act is not explicitly described orillustrated in the figures.

While this disclosure has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments, as well as other embodiments of thedisclosure, will be apparent to persons skilled in the art uponreference to the description. It is therefore intended that the appendedclaims encompass any such modifications or embodiments.

1. A method, comprising: bonding a first panel of a first material to abase panel in a first gas atmosphere, wherein multiple hermeticallysealed first cavities encapsulating gas of the first gas atmosphere areformed between the first panel and the base panel; and bonding a secondpanel of a second material to the base panel, wherein multiple secondcavities are formed between the second panel and the base panel, thefirst panel and the second panel being bonded to an identical surface ofthe base panel.
 2. The method of claim 1, wherein the second panel isbonded in a second gas atmosphere different from the first gasatmosphere, and the second cavities are hermetically sealed andencapsulate gas of the second gas atmosphere.
 3. The method of claim 2,further comprising: singulating the bonded panels into multiple devices,wherein each of the devices comprises at least two cavities, wherein afirst cavity of the at least two cavities comprises gas of the first gasatmosphere and a second cavity of the at least two cavities comprisesgas of the second gas atmosphere.
 4. The method of claim 1, wherein atleast one of the first material and the second material is airtight. 5.The method of claim 1, wherein at least one of the first material andthe second material comprises at least one of a semiconductor material,a glass material, a ceramic material.
 6. The method of claim 1, whereinat least one of the first panel and the second panel comprises multiplerecesses, is bonded to a planar surface of the base panel, and thecavities formed between the base panel and the at least one of the firstpanel and the second panel are formed by sections of the planar surfaceand the recesses.
 7. The method of claim 1, wherein at least one ofbonding the first panel and bonding the second panel comprises at leastone of anodic bonding, soldering, gluing, metal-to-metal bonding.
 8. Themethod of claim 1, further comprising: at least partially removingmaterial from the first panel before bonding the second panel.
 9. Themethod of claim 1, further comprising: arranging electronic componentsover the base panel before bonding the first panel and bonding thesecond panel, wherein at least one of the electronic components isarranged in at least one of the first cavities and the second cavitiesafter bonding the first panel and bonding the second panel.
 10. Themethod of claim 1, wherein the base panel comprises a semiconductormaterial and the method further comprises: integrating electroniccomponents in the semiconductor material of the base panel beforebonding the first panel and bonding the second panel, wherein at leastone of the integrated electronic components is arranged in at least oneof the first cavities and the second cavities after bonding the firstpanel and bonding the second panel.
 11. The method of claim 1, whereinat least one of the base panel, the first panel and the second panelcomprises one or more from a group consisting of: electrical throughconnections, conductor lines, electrical redistribution layers, opticalconnections, fluidic connections.
 12. A method, comprising: bonding afirst panel of a first airtight material to a surface of a base panel ina first gas atmosphere, wherein multiple hermetically sealed firstcavities encapsulating gas of the first gas atmosphere are formedbetween the first panel and the base panel; and bonding multiple caps ofa second airtight material to the surface of the base panel in a secondgas atmosphere different from the first gas atmosphere, wherein multiplehermetically sealed second cavities encapsulating gas of the second gasatmosphere are formed between the multiple caps and the base panel. 13.The method of claim 12, further comprising: singulating an arrangementcomprising the base panel, the first panel and the multiple caps intomultiple devices, wherein each of the devices comprises at least twocavities, wherein a first cavity of the at least two cavities comprisesgas of the first gas atmosphere and a second cavity of the at least twocavities comprises gas of the second gas atmosphere.
 14. A device,comprising: a first cavity formed by a first cap of an airtight materialbonded to a base, wherein the first cavity hermetically seals a firstgas and encapsulates a first electronic component; and a second cavityformed by a second cap of an airtight material bonded to the base,wherein the second cavity hermetically seals a second gas different fromthe first gas and encapsulates a second electronic component.
 15. Thedevice of claim 14, wherein the base comprises a semiconductor materialand at least one of the first electronic component and the secondelectronic component is integrated in the semiconductor material. 16.The device of claim 14, wherein the device comprises at least one of amicroelectromechanical system, a microfluidic system, a lab-on-a-chip.17. The device of claim 14, wherein the device comprises a photoacousticgas sensor, the first electronic component comprises an IR emitter, thesecond electronic component comprises a microphone, the first gas is aprotective gas, and the second gas is a reference gas.